Wurmple will evolve into either Silcoon or Cascoon starting at level 7 depending on its personality value. As personality values cannot be influenced or seen by the player, what a given Wurmple will evolve into is essentially random. From there, the Silcoon or Cascoon will evolve again starting at level 10 into Beautifly or Dustox respectively.

Biology

Wurmple is a small, caterpillar-like Pokémon. Its body is mainly red with a cream underside and face. It has large yellow eyes with dark pupils. It has one sharp yellow stinger on its head and two of them on its rear. It has a tall, erect, red spine behind its forehead and a similar, smaller spine behind that. It has small spikes running down the top portions of its body and five pairs of stubby white limbs.

Wurmple has suction pads at the tips of its feet, which allow it to cling to glass or tree branches without slipping. It can spit a white silk that turns gooey when exposed to the air. It can release poison from its tail spikes, which can weaken and poison foes. Wurmple lives in forests. It eats leaves and pulls bark off trees to feed on the sap.

In the anime

Wurmple in the anime

Major appearances

Jessie also captured a Wurmple in All in a Day's Wurmple. Jessie's Wurmple evolved into a Cascoon in the same episode that May's Wurmple evolved in, and later evolved into Dustox, which was also the same episode where May's Silcoon had evolved into a Beautifly.

Pokédex entries

Using the spikes on its rear end, Wurmple peels the bark off trees and feeds on the sap that oozes out. This Pokémon's feet are tipped with suction pads that allow it to cling to glass without slipping.

Using the spikes on its rear end, Wurmple peels the bark off trees and feeds on the sap that oozes out. This Pokémon's feet are tipped with suction pads that allow it to cling to glass without slipping.

Trivia

Wurmple shares its species name with Caterpie. They are both known as the Worm Pokémon.

Wurmple is the only Pokémon whose branched evolutions evolve further. All other Pokémon with a branch in their evolutionary line either evolve once before the branch or do not have any other evolutionary event besides the one which is branched.

Wurmple is the only Pokémon whose evolution is directly influenced by its personality value. Pokémon whose evolution is influenced by their gender are also technically evolving based on their personality value, although unlike Wurmple, their determined evolution can be known in advance.